A Coordinate Reference System that is defined for and usually used in a contextually local sense, which may be an area, significantly less than the complete surface of the earth or a moving platform and its vicinity.

For example local engineering and architectural coordinates, grids, and drawings; also: vessel navigation systems and CRSs associated with orbiting spacecraft.

A transformation of engineering coordinates to geodetic coordinates may or may not be possible depending on whether such operation parameters have been determined (or defined).

An Engineering CRS may be defined to describe geometry that is local to the context of a moving platform, such as a car, a ship, an aircraft or a spacecraft.

• Transformation of such engineering coordinates to geodetic coordinates involves time dependent operation parameters and, when repeated at (regular) time-intervals, will result in a record of the "track" of the moving platform.

• Additionally such a transformation may be used for real-time navigation of the platform.

• The term "vicinity of the moving platform" may constitute an area varying from the immediate surroundings of the platform to the entire earth, the latter being the case in a number of space applications.

i, j, k Cartesian coordinates in an engineering coordinate reference system, (integer or real)